The present invention relates to technique for a touch-sensor devices, which are also referred to as touch panels, display devices provided with a touch-sensor function, electronic devices, etc.
In various electronic devices and display devices such as smartphones, touch-sensor devices are mounted as input means. Examples of the touch-sensor devices include touch-sensor devices dedicated to a touch-sensor function, touch-sensor-equipped display devices of an external type or a cover-integrated type, and touch-sensor-equipped display devices in which electrodes constituting a touch-sensor device are built in a display panel. The touch-sensor-equipped display devices of the external type or the cover-integrated type are also referred to as on-cell-type touch-sensor-equipped display devices. The touch-sensor-equipped display devices in which the electrodes of the touch sensor are built in the display panel are also referred to as in-cell-type touch-sensor-equipped display devices. Examples of the touch-sensor-equipped display devices include liquid-crystal touch panel modules used in liquid-crystal display devices.
A touch-sensor device of an electrostatic capacitance type has touch drive electrodes (also referred to as transmitter electrodes) and touch detection electrodes (also referred to as receiver electrodes). A unit of touch detection is formed by intersections of electrode pairs of the touch drive electrodes and the touch detection electrodes. For example, the plurality of touch drive electrodes are parallel to an in-plane horizontal direction in a surface serving as a touch detection area, and the plurality of touch detection electrodes are parallel to an in-plane perpendicular direction. The unit of touch detection is formed by a capacitor formed in the vicinity of, for example, intersecting parts, of electrode pairs of the touch drive electrodes and the touch detection electrodes. In the surface of the touch detection area, the plurality of units of touch detection are formed in matrix. The touch-sensor device has a circuit unit coupled to the electrode pairs of the above-described touch drive electrodes and the touch detection electrodes. When the capacitance of the capacitor is changed when an electrical conductor such as a finger is close to or in contact with the surface of the touch detection area, the circuit unit detects the change in the capacitance as an electric signal. By virtue of this, the touch-sensor device detects the presence/absence, position, etc. of a touch to the touch detection area.
The on-cell-type touch-sensor-equipped display device has, for example, a configuration in which a touch-sensor device or a touch-sensitive layer is externally coupled to a front surface side in which a display area of a liquid-crystal panel unit is formed. Alternatively, the on-cell-type touch-sensor-equipped display device has a configuration in which electrodes of a touch sensor are integrally formed on a cover composed of glass, plastic, or the like provided in the front surface side of a liquid-crystal display panel unit.
The in-cell-type touch-sensor-equipped display device has, for example, a configuration in which at least one of the touch drive electrodes and the touch detection electrodes serving as the electrodes composing the above-described touch sensor, for example, the touch drive electrodes are built in a liquid-crystal display panel unit. The in-cell-type touch-sensor-equipped display device having this configuration has, for example, a configuration in which shared electrodes integrating a common electrode of the liquid-crystal display device and the above-described touch drive electrodes are provided on a TFT board side serving as a first board structure, and the above-described touch detection electrodes are provided on a color filter board side serving as a second board structure.
Examples of conventional techniques about the above-described touch sensor include Japanese Patent Application Laid-Open Publication No. 2009-244958 (Patent Literature 1) and Japanese Patent Application Laid-Open Publication No. 2009-258935 (Patent Literature 2).
Patent Literature 1 describes configuration examples of an in-cell-type touch-sensor-equipped liquid-crystal display device.
Patent Literature 2 describes configuration examples of electrodes and wirings relating to a touch sensor. Patent Literature 2 describes the example in which, as a configuration example of routed wirings between electrodes of circuit-side connection terminals, a connecting side, and a touch detection area, the wiring lengths thereof are mutually different. Patent Literature 2 also describes a configuration example in which the widths of the routed wirings are mutually different.